New Plants Can Detect Bombs by Changing Color

Professor June Medford with her bomb-sniffing plants.
(Colorado State University)

A scientist at Colorado State University has developed a way to make everyday plants one of the first lines of defense in the war on terror.

Lab work currently underway makes green plants turn white if they detect explosive, biological or chemical weapons in their environment. Imagine someone walking by these plants in an airport with hidden explosives -- and the plants changing color to alert security.

Professor June Medford and fellow scientists on the campus of Colorado State University are now working with the U.S. Departments of Defense and Homeland Security to develop high-tech plants for use in airports and other public areas.

"We actually modify the seed," Medford told Fox News, "and then it's a trait that is stable and stays with it forever. It's very empowering because it will tell you that there's an explosive around: 'get the security guys here!'"

The idea may sound like science fiction, but Medford says using plants to detect chemicals and pathogens makes perfect sense. Just think of bananas, which are picked green but won't ripen in northern climates unless exposed to the gas ethylene. Medford has likewise modified her plants to react when exposed to specific agents, at which point they turn from green to white.

"It's a program we can put in any plant species," Medford said.

Like most living organisms, plants have built-in defense mechanisms. "But plants can't run and hide from a threat," Medford explained. "They have to have a way to detect and respond and they do that already. But they detect bugs and things like that. What we've done is teach them a new trick ... to detect things we care about."

Medford's list of possibilities seems endless. In addition to explosives detection, plants can be modified to react to disease-causing microbes, pollutants, even carbon monoxide or radon gases in homes. Medford also says members of the military in Iraq and Afghanistan could use these greens to detect improvised explosive devices (IEDs).

But don't get too curious about the science behind it all. Speaking with Fox News, there were numerous times Medford was unable to answer a question, for security purposes. The delicate nature of national security, she explains, means keeping some of this stuff secret.

"When you have a system where the bad guys don't even know that there's a detector there, I think it's very, very powerful," Medford said. "It can tell our security guys, the police, where to come and and where to look."

Before it becomes practical, however, the time it takes a plant to turn from green to white has to be reduced, Medford said. "It works right now, but it'll work in hours; we need to cut it down to minutes and seconds. And we think that's very doable -- and indeed we're getting some very good data to support that."

The hope, according to Medford, is that one day the United States will use plants as an additional layer of security, not as a replacement to current systems. Her plants have the same sensitivity as bomb-sniffing dogs, and being stuck in the soil rather than walking around sniffing things has some inherent advantages.

"I've talked to the world's leading people who work with dogs," she said, "and it's really hard to get good data on dogs. Dogs are very, very good sometimes, and then dogs get distracted. My plants don't get distracted."

Dogs, however, do carry the element of surprise, Medford says, which is why the layered approach is important. One of the other advantages of using plants as enemy detectors, is they come pretty cheap. Because these plants can be produced on a large scale, they cost less than a penny per unit.

What's more, they reset. Medford tells Fox News that once the offensive substance has been removed the plant will go back to original color and can be used again and again. Pending the outcome of further testing, first alert plants could be in use in just a few years.